Optics Basics

Before you can understand myopia or choose your glasses, it helps to fill in the basics of optics. This module explains how light travels, how it refracts, how lenses form images, and how the human eye works like a small camera, in the most intuitive terms: light bends whenever it crosses into a medium with a different density, a convex lens pulls parallel rays together while a concave lens spreads them apart, and the eye itself is an optical system built from the cornea, the lens, the vitreous body, and the retina.